In general, according to a smart parking assist system (SPAS), a driver selects a parking mode and a parking direction within a parking space, and the SPAS searches a parkable empty space, a target vehicle, and surrounding obstacles to generate and follow a parking trajectory and park the vehicle in the space.
The smart parking assist system (SPAS) according to the related art described above is referred to as a function of recognizing the space by front/rear/side ultrasonic sensors and automatically assisting the parking without manipulating a steering wheel using voice and image guidance, and a perpendicular parking and a parallel parking system have been developed. The driver only needs to manipulate a transmission and an acceleration pedal according to the voice guidance.
However, the smart parking assist system (SPAS) according to the related art may find the parkable space only in the case in which the vehicle scans while being spaced apart from the parking space using left/right/side ultrasonic sensors to search the parking space.
In addition, since the smart parking assist system (SPAS) according to the related art recognizes the parkable space using the ultrasonic sensors, it is difficult to quickly recognize the parking space out of a searchable range by the ultrasonic sensors.